Implement move_projects folder moves

[deverman]

Summary

• Adds CLI and MCP surfaces for move_projects / focusrelay move-projects.
• Supports homogeneous project moves to a folder by ID or to the root library when destinationID is omitted.
• Implements bridge execution with documented Omni Automation section APIs: flattenedProjects, flattenedFolders, moveSections, folder.beginning/ending, and library.beginning/ending.
• Tightens move validation so task moves cannot target folders and project moves cannot target projects/parent tasks/inbox.

Stack / merge order

Depends on PR #49. Merge this after #49, then continue to the final docs/AI guidance issue.

Validation

• node --check Plugin/FocusRelayBridge.omnijs/Resources/BridgeLibrary.js
• swift test
• ./scripts/install-plugin.sh
• Restarted OmniFocus
• focusrelay move-projects --help
• Live preview against temp project + Travel folder: accepted valid folder, rejected invalid folder
• Live mutation against temp project: moved to Travel with verify, moved back to root library with verify, deleted temp project and confirmed deletion

Refs #35

[deverman]

Stack note: this PR is intentionally based on #49 (issue-47-mutation-dispatch-reliability). Merge #49 first, then #50. After #50, continue with the docs/AI guidance issue.

[deverman]

Stack note update: #51 (issue #48 bridge mutation helper refactor) is now stacked on this PR. Merge #49 first, then #50, then #51.

[deverman]

Validation update after rebasing onto current master:

• node --check Plugin/FocusRelayBridge.omnijs/Resources/BridgeLibrary.js passed.
• swift test passed: 95 Swift Testing tests.
• Reinstalled the OmniFocus plugin with ./scripts/install-plugin.sh and fully restarted OmniFocus.
• ./.build/debug/focusrelay bridge-health-check returned ok.
• ./.build/debug/focusrelay move-projects --help exposes the expected CLI surface.
• Live UAT used temporary OmniFocus data only:
  • created temporary project nqM8hf6yzMn and temporary folder b9ecB_0FfLP
  • previewed move to folder successfully
  • previewed invalid folder ID and got per-item failure: Destination folder ID not found.
  • moved temporary project to temporary folder with --verify
  • moved temporary project back to root library with --verify
  • deleted the temporary project/folder and confirmed both no longer exist

Final PR diff against master is scoped to move_projects: bridge implementation, CLI/MCP entry points, shared validation, and parser/model tests.